The present disclosure generally relates to communication devices and methods and, more particularly, to the full duplex communication devices and methods which may rapidly establish the network connection.
In the process of developing new industrial standards or new applications, existing technologies are often incorporated to shorten the time for research and improve the system stability. The existing technologies, however, may need to be modified to fit in the new standards or new applications.
For example, in the High-Definition Multimedia Interface (HDMI), the fast Ethernet technology, i.e., 100 BASE-TX of the IEEE 802.3u standard, is used in the HDMI Ethernet Channel (HEC) communication. Although both the 100 BASE-TX transceivers and the HEC transceivers may operate in the full duplex mode, the 100 BASE-TX transceiver transmits signals on one twisted pair of conductors and receives signals on another twisted pair of conductors. On the other hand, the HEC transceiver may transmit and receive signals on the same twisted pair of conductors simultaneously. When the near-end HEC transceiver receives the signals transmitted from the far-end HEC transceiver, the near-end HEC transceiver therefore may also receive the signals transmitted by itself. When the near-end HEC transceiver and the far-end HEC transceiver transmit the same signals, both HEC transceivers may not differentiate the near-end signals and the far-end signals and therefore fail to function correctly.
Besides, in the idle mode or in the connection establishment process, the HEC transceivers on both ends need to transmit idle signals. The HEC transceivers continuously and repeatedly transmit the pseudo random code of several thousand bits as the idle signals. The HDMI standard does not adopt the master-slave mechanism and does not require the near-end and the far-end HEC transceivers to use different scramblers. Thus, in the idle mode or in the connection establishment process, the near-end and the far-end HEC transceivers may transmit the same idle signals and therefore fail to function correctly.
Moreover, although the HEC transceivers shall transmit the signals with a 125 MHz frequency, there still may be a difference existed between the transmission frequencies of the transceivers on both ends. For example, a difference with ±200 ppm of the transmission frequency is tolerable in some technical standards. Therefore, even if the near-end and the far-end HEC transceivers are configured to transmit the idle signals from different positions of the same pseudo random code, the difference between the transmission frequencies may still cause the near-end and the far-end HEC transceivers to transmit the same idle signals after a period of time. The HEC transceivers may still fail to function correctly in this configuration.
Furthermore, the transceivers need to establish the network connection more rapidly so as to support the advanced features, e.g., the Energy Efficient Ethernet (EEE) standard defined by IEEE 802.3 az task force. The HEC transceivers need to rapidly establish the network connection before entering the quiet mode (defined in the EEE standard) so that the HEC transceivers may obtain a better signal-to-noise ratio (SNR) and therefore maintain the network connection after leaving the quiet mode.